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(No Model.) 0. J-. BEALE.

V ROTARY CUTTER. No. 277,405. Patented May 8,1883.

WI TNEEEEEI [NVEN TUE-I UNITED STATES PATENT OFFICE.

OSCAR J. BEALE, OF PROVIDENCE,

SHARPE MANUFACTURING ROTARY CUTTER.

SPECIFICATION forming part of Letters Patent No. 277,405, dated May 8,1883. I

Application filed November 13. 1882. (No model) To all whom it mayconcern:

Be it known that LIOSGAR J. BEALE, of the city and county of Providence,and State of Rhode Island, have invented a new and useful Improvementin' Rotary Cutters; hereby declare that the following is a full, clear,and exact description of the same, reference being bad to theaccompanying drawings, forming part of this specification.

This invention has reference to an improvementin cutters formilling-machines, and is particularly applicable to machines for cuttingthe teeth into gear-wheels and similar cuttingtools.

The object of the cutting-edge and facilitate the same. y

The invention consists in the peculiar and novel construction of thecutting-tool, by which the central portion of the cutting-face isremoved, and in the method or process by which the same is removed, aswill be more fully set forth hereinafter.

Figure 1' is a view of a rotary cutter, showing the position of a reamerused to cut away the central portion of the cutting-face. Fig. 2 isan'enlarged sectional view of my improved cutter. Fig. 3 is a view ofthe cutting-face of my improved cutter. Fig. 4 is a cross-section of myimproved cutter. I

In cuttingtools it is important that the cutting edge or corner shallform an angle of no more than a right angle, or an angle of ninetydegrees. A lesser or more pointed angle is very desirable, as it willproduce a cleaner cut;

invention is to improve the grinding of the but a greater or more obtuseangle requires a large amount of power to force the cutter through themetal, and makes a very imperfect cut, as the metal has to be brokenaway instead of being cut. The cutting-faces of cutand I' ters have tobe ground to restore the sharp cutting edge or corner, and in rotarycutters, such as shown in Fig. *1, the cutting-faces must be ground onthe side of a revolving grinder, which attacks the edges more readilythan the center, and such cutting-faces, even when the greatest care andskill are employed, will be slightly rounded. By removing the centralportion of the cutting-face the same is not only more quickly ground, asonly the edges have to be ground, but a sharp right-angled cutting-edgeis readily produced.

In the drawings, B is the central cavity. edges.

Ido not wish to confine myself to rotary cutters, or cutters in whichthe cutting-face is at right angle to the direction of motion, as theremoval of the central portion of the face to be ground in any cutterfacilitates the grinding and secures a truer and better face.

In constructing rotary cutters for millingmachines two methods may beused to remove the central portion of the cutting-face. first is shownin Fig. 1, in which the drill F is shown in the position when thecavityB is out after the cutters A A have been formed on the disk. Thesecond method consists in first drilling the holes into the edge of thedisk and then cutting out the spaces between the teeth.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- The rotary cutter, substantially as described, havingcavities B formed in the front faces of the cutting-teeth, as described.

OSCAR J. BEALE,

A A are the cutter-teeth. e e are the cutting- Witnesses:

J. A. MILLER, J r., M. F. BLIGH.

The

